Issue #3484792: Update Page Manager integration for latest version

Closes #3484792

metatag_mobile/tests/src/Functional/TestCoreTagRemoval.php

@@ -17,6 +17,11 @@ class TestCoreTagRemoval extends BrowserTestBase {
   use FieldUiTestTrait;
   use MetatagHelperTrait;
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * {@inheritdoc}
    */